WASHINGTON, Dec. 6, 2012 /PRNewswire-USNewswire/ -- A new analysis of U.S. Census Bureau data by the Center for Immigration Studies projects the impact of immigration on the size and composition of the U.S. population. The findings reveal that immigration makes for a much larger overall population, while having only a minimal effect on slowing the aging of American society.

Steven Camarota, the Center's Director of Research, notes, "There is simply no question immigration makes for a much larger and more densely settled country, but it is not a cure for an aging society."

If net immigration (difference between those coming and going) unfolds as the Census Bureau estimated in the last set of projections, the nation's population will increase from 309 million in 2010 to 436 million in 2050 — a 127 million (41 percent) increase.

The projected increase of 127 million is larger than the combined populations of the U.K. and France.

By itself future immigration will account for 96 million (75 percent) of future population growth.

The immigrant (legal and illegal) share of the population will reach one in six U.S. residents by 2030, a new record, and nearly one in five residents by 2050.

The Center for Immigration Studies, as well as other researchers, has found that immigration levels have fallen somewhat in recent years. While there is no way to know if the level will remain lower, this change can be incorporated into these projections:

A one-third reduction in the Census Bureau's level of net immigration over the next four decades (2010-2050) produces a total U.S. population of 404 million in 2050 — a 95 million increase over 2010.

Even if immigration is half what the Census Bureau expects, the population will still grow 79 million by 2050, with immigration accounting for 61 percent of population growth.

The underlying level of immigration is so high, even assuming a substantial reduction would still add tens of millions of new residents to the U.S. population and account for most of the population growth.

Consistent with prior research, the projections show immigration only slightly increases the working-age (18 to 65) share of the population. Assuming the Census Bureau's immigration level, 58 percent of the population will be of working-age in 2050, compared to 57 percent if there is no immigration.

Raising the retirement age by one year would have a larger positive impact on the working-age share over the next 40 years then would the Census Bureau's projected level of net immigration (68 million).

While immigrants tend to arrive relatively young and have higher fertility than natives, immigrants age just like everyone else, and the differences with natives are not large enough to fundamentally increase the share of the population who are potential workers.

Discussion

While immigration is the primary driver of population growth, even without immigration, the population will increase by 31 million by 2050. The long term trend in immigration has been a steady increase, and this seems likely to continue once the U.S. economy recovers. But, even if immigration is half of what the Census Bureau expected in the 2008 projections, the U.S. population will still grow by 79 million by 2050, with immigration accounting for 61 percent of population growth.

The fundamental question for the American public and policy makers is whether a much larger population and the resulting greater population density will add to or diminish the quality of life in the United States. Immigration is a discretionary policy of the government and can be changed. These projections show us one possible future. We must decide as a country if this is the future we want.

Methodology

The report contains a detailed explanation of the study's methodology. In sum, the Center for Immigration and Decision Demographics of Arlington, Virginia developed the projections model used in this analysis. We first replicated the official 2008 Census Bureau projections, their last full set of projections, by race/ethnicity. This was possible because the Census Bureau Projections Branch was kind enough to share unpublished data that it used to generate its last major series of projections. In total, the Bureau's net immigration projection is 68.3 million for the period 2010 to 2050. We vary this base level of immigration to discern its' impact on population size and composition. These projections follow the Census Bureau's assumptions about future levels of immigration and death and birth rates, including a decline in the birth rate for Hispanics.

The Center for Immigration Studies is an independent, non-partisan, non-profit, research organization. Since its founding in 1985, the Center has pursued a single mission – providing immigration policymakers, the academic community, news media, and concerned citizens with reliable information about the social, economic, environmental, security, and fiscal consequences of legal and illegal immigration into the United States.